Publication Type
Journal
Journal Name
Nuclear Science and Engineering
Publication Date
Page Numbers
111 to 125
Volume
177
Issue
2
Abstract
We have implemented a new multilevel parallel decomposition in the Denovo dis-
crete ordinates radiation transport code. In concert with Krylov subspace iterative
solvers, the multilevel decomposition allows concurrency over energy in addition to
space-angle, enabling scalability beyond the limits imposed by the traditional KBA
space-angle partitioning. Furthermore, a new Arnoldi-based k-eigenvalue solver has
been implemented. The added phase-space concurrency combined with the high-
performance Krylov and Arnoldi solvers has enabled weak scaling to O(100K) cores
on the Jaguar XK6 supercomputer. The multilevel decomposition provides sucient
parallelism to scale to exascale computing and beyond.
